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91.
Giorgia Letizia Marcone Elisa Binda Francesca Berini Flavia Marinelli 《Biotechnology advances》2018,36(2):534-554
Glycopeptide antibiotics are drugs of last resort for treating severe infections caused by multi-drug resistant Gram-positive pathogens. First-generation glycopeptides (vancomycin and teicoplanin) are produced by soil-dwelling actinomycetes. Second-generation glycopeptides (dalbavancin, oritavancin, and telavancin) are semi-synthetic derivatives of the progenitor natural products. Herein, we cover past and present biotechnological approaches for searching for and producing old and new glycopeptide antibiotics. We review the strategies adopted to increase microbial production (from classical strain improvement to rational genetic engineering), and the recent progress in genome mining, chemoenzymatic derivatization, and combinatorial biosynthesis for expanding glycopeptide chemical diversity and tackling the never-ceasing evolution of antibiotic resistance. 相似文献
92.
Andrea Bolognesi Letizia Polito Fabiola Olivieri Paola Valbonesi Luigi Barbieri M. Giulia Battelli M. Vittoria Carusi Eugenio Benvenuto Francesca Del Vecchio Blanco Antimo Di Maro Augusto Parente Mario Di Loreto Fiorenzo Stirpe 《Planta》1997,203(4):422-429
New single-chain (type 1) ribosome-inactivating proteins (RIPs) were isolated from the seeds of Basella rubra L. (two proteins) and from the leaves of Bougainvillea spectabilis Willd. (one protein). These RIPs inhibit protein synthesis both in a cell-free system, with an IC50 (concentration causing 50% inhibition) in the 10−10 M range, and by various cell lines, with IC50s in the 10−8–10−6 M range. All three RIPs released adenine not only from rat liver ribosomes but also from Escherichia coli rRNA, polyadenylic acid, herring sperm DNA, and artichoke mottled crinkle virus (AMCV) genomic RNA, thus being polynucleotide:adenosine
glycosidases. The proteins from Basella rubra had toxicity to mice similar to that of most type 1 RIPs (Barbieri et al., 1993, Biochim Biophys Acta 1154: 237–282) with
an LD50 (concentration that is 50% lethal) ≤ 8 mg · kg−1 body weight, whilst the RIP from Bougainvillea spectabilis had an LD50 >32 mg · kg−1. The N-terminal sequence of the two RIPs from Basella rubra had 80–93% identity, whereas it differed from the sequence of the RIP from Bougainvillea spectabilis. When tested with antibodies against various RIPs, the RIPs from Basella gave some cross-reactivity with sera against dianthin 32, and weak cross-reactivity with momordin I and momorcochin-S, whilst
the RIP from Bougainvillea did not cross-react with any antiserum tested. An RIP from Basella rubra and one from Bougainvillea spectabilis were tested for antiviral activity, and both inhibited infection of Nicotiana benthamiana by AMCV.
Received: 5 March 1997 / Accepted: 27 May 1997 相似文献
93.
94.
The role of alien fish (the centrarchid Micropterus salmoides) in lake food webs highlighted by stable isotope analysis
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Maria Letizia Costantini Pasquale Carlino Edoardo Calizza Giulio Careddu Davide Cicala Simona Sporta Caputi Federico Fiorentino Loreto Rossi 《Freshwater Biology》2018,63(9):1130-1142
95.
Laura Pizzuti Maddalena Barba Diana Giannarelli Domenico Sergi Claudio Botti Paolo Marchetti Michele Anzà Marcello Maugeri‐Saccà Clara Natoli Simona Di Filippo Teresa Catenaro Federica Tomao Antonella Amodio Silvia Carpano Letizia Perracchio Marcella Mottolese Luigi Di Lauro Giuseppe Sanguineti Anna Di Benedetto Antonio Giordano Patrizia Vici 《Journal of cellular physiology》2016,231(11):2541-2547
To report the results of the DECT trial, a phase II study of locally advanced or operable HER2‐positive breast cancer (BC) treated with taxanes and concurrent anthracyclines and trastuzumab. Eligible patients (stage IIA‐IIIB HER2‐positive BC, 18–75 years, normal organ functions, ECOG ≤1, and left ventricular ejection fraction (LVEF) ≥55%) received four cycles of neoadjuvant docetaxel, 100 mg/m2 intravenously, plus trastuzumab 6 mg/kg (loading dose 8 mg/kg) every 3 weeks, followed by four 3‐weekly cycles of epirubicin 120 mg/m2 and cyclophosphamide, 600 mg/m2, plus trastuzumab. Primary objective was pathologic complete response (pCR) rate, defined as ypT0/is ypN0 at definitive surgery. We enrolled 45 consecutive patients. All but six patients (13.3%) completed chemotherapy and all underwent surgery. pCR was observed in 28 patients (62.2%) overall and in 6 (66.7%) from the inflammatory subgroup. The classification and regression tree analysis showed a 100% pCR rate in patients with BMI ≥25 and with hormone negative disease. The median follow up was 46 months (8–78). Four‐year recurrence‐free survival was 74.7% (95%CI, 58.2–91.2). Seven patients (15.6%) recurred and one died. Treatment was well tolerated, with limiting toxicity being neutropenia. No clinical cardiotoxicity was observed. Six patients (13.4%) showed a transient LVEF decrease (<10%). In one patient we observed a ≥10% asymptomatic LVEF decrease persisting after surgery. Notwithstanding their limited applicability due to the current guidelines, our findings support the efficacy of the regimen of interest in the neoadjuvant setting along with a fairly acceptable toxicity profile, including cardiotoxicity. Results on BMI may invite further assessment in future studies. J. Cell. Physiol. 231: 2541–2547, 2016. © 2016 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals, Inc. 相似文献
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97.
Gino Giannaccini Roberto Lupi M. Letizia Trincavelli Renzo Navalesi Laura Betti Piero Marchetti Antonio Lucacchini Silvia Del Guerra Claudia Martini 《Journal of cellular biochemistry》1998,71(2):182-188
Current information on pancreatic islet sulfonylurea receptors has been obtained with laboratory animal pancreatic β cells or stable β-cell lines. In the present study, we evaluated the properties of sulfonylurea receptors of human islets of Langherans, prepared by collagenase digestion and density-gradient purification. The binding characterisitics of labeled glibenclamide to pancreatic islet membrane preparations were analyzed, displacement studies with several oral hypoglycemic agents were performed, and these latter compounds were tested as for their insulinotropic action on intact human islets. [3H]glibenclamide saturable binding was shown to be linear at ≤0.25 mg/ml protein; it was both temperature and time dependent. Scatchard analysis of the equilibrium binding data at 25°C indicated the presence of a single class of saturable, high-affinity binding sites with a Kd value of 1.0 ± 0.07 nM and a Bmax value of 657 ± 48 fmol/mg of proteins. The displacement experiments showed the following rank order of potency of the oral hypoglycemic agents we tested: glibenclamide = glimepiride > tolbutamide > chlorpropamide ≫ metformin. This binding potency order was parallel with the insulinotropic potency of the evaluated compounds. J. Cell. Biochem. 71:182–188, 1998. © 1998 Wiley-Liss, Inc. 相似文献
98.
99.
Elisabetta Albi Maria Letizia Tomassoni Mariapia Viola-Magni 《Cell biochemistry and function》1997,15(3):181-190
Nuclear membrane fluidity is measured in rat liver by use of the fluorescence anisotropy of two probes: diphenylhexatriene and its cationic derivative trimethylammonium-diphenylhexatriene. It has been shown that, in 2-month-old rat liver cells, the bilayer surface is less fluid than the hydrophobic core. The fluidity was higher in 6-day-old rat liver nuclei, in which both the amount of cholesterol and the cholesterol/phospholipid ratio decreased. The influence of the single phospholipids, and in particular of phosphatidylcholine, has been studied by increasing the phosphatidylcholine with a choline base exchange reaction in isolated nuclear membranes. After this reaction, the fluorescence anisotropy of the bilayer surface increased, whereas at the hydrophobic core it decreased. Analysis of fatty acid composition shows an increase of phosphatidylcholine unsaturated fatty acids. The results show that the fluidity of nuclear membranes changes in relation to the lipid content and to the fatty acid composition. The role of nuclear membrane fluidity in cell function is discussed. © 1997 John Wiley & Sons, Ltd. 相似文献